1. Field
The present disclosure relates to a vector replicable in E. coli and a cell of the genus Komagataeibacter, a cell comprising the vector, a method of producing a target protein using the cell, and a method of evaluating a candidate promoter using the cell, as well as related methods and compositions.
2. Description of the Related Art
Cellulose produced by culturing microorganisms exists as a primary structure of β-1,4 glucan, which are polysaccharides composed of glucose subunits. The β-1,4-glucans form a network structure of fibril aggregates. This cellulose is also called ‘biocellulose’ or ‘microbial cellulose.’
Unlike plant cellulose, microbial cellulose is pure cellulose entirely free of lignin or hemicelluloses. The fiber width of microbial cellulose is 100 nm, which is less than that of plant cellulose. Microbial cellulose has wetting and water absorption properties, high strength, high elasticity, and high heat resistance, etc. Due to these properties, microbial cellulose has been developed and applied to a wide variety of fields, such as beauty products, medical fields, dietary fibers, acoustic diaphragms, functional films, etc.
Several cellulose-producing strains have been reported, including Acetobacter, Agrobacteria, Rhizobia, and Sarcina. Among these, Komagataeibacter xylinum (also called ‘Acetobacter xylinum’) is known as a particularly excellent strain. A static aerobic culture of these microbes produce a three-dimensional network of cellulose formed as a thin film on the surface of the culture medium.
To improve the utility of these strains, however, shuttle vectors are needed to provide more efficient genetic manipulation. Whereas a cloning vector requires only a replication origin for maintenance of a plasmid form within a strain, a selection marker gene for selection of a strain retaining the vector, and a multi-cloning site (MCS) for cloning of a foreign gene, shuttle vectors should be able to maintain a plasmid in a plurality of strains. Typically, shuttle vectors can be used to clone plasmid in E. coli and transform another strain. There is a need for shuttle vectors that are able to replicate in E. coli and a cell of the genus Komagataeibacter, particularly Komagataeibacter xylinum. 